This centralizes filestat logic by making our own `Stat_t` similar to
`syscall.Stat_t`. This exposes utilities in the platform package and
adds a new function `FS.Stat` which avoids having to use `fs.File` to
get the same info. Doing so at the FS abstraction allows us to optimize
how it is implemented internally using portable means (e.g.
`os.StatFile`) or OS-specific means where necessary, e.g. in windows.
This also ensures `platform.OpenFile` returns syscall.Errno and
centralizes error checking with a new `require.EqualErrno` test.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This makes it easier to do maintenance by hiding the implementation
details of using a proxy module to test host modules. What happens is we
skip logging of these proxy modules, which makes it easier to see what
log affects a change has.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This PR follows @hafeidejiangyou advice to not only enable end users to
avoid reflection when calling host functions, but also use that approach
ourselves internally. The performance results are staggering and will be
noticable in high performance applications.
Before
```
BenchmarkHostCall/Call
BenchmarkHostCall/Call-16 1000000 1050 ns/op
Benchmark_EnvironGet/environGet
Benchmark_EnvironGet/environGet-16 525492 2224 ns/op
```
Now
```
BenchmarkHostCall/Call
BenchmarkHostCall/Call-16 14807203 83.22 ns/op
Benchmark_EnvironGet/environGet
Benchmark_EnvironGet/environGet-16 951690 1054 ns/op
```
To accomplish this, this PR consolidates code around host function
definition and enables a fast path for functions where the user takes
responsibility for defining its WebAssembly mappings. Existing users
will need to change their code a bit, as signatures have changed.
For example, we are now more strict that all host functions require a
context parameter zero. Also, we've replaced
`HostModuleBuilder.ExportFunction` and `ExportFunctions` with a new type
`HostFunctionBuilder` that consolidates the responsibility and the
documentation.
```diff
ctx := context.Background()
-hello := func() {
+hello := func(context.Context) {
fmt.Fprintln(stdout, "hello!")
}
-_, err := r.NewHostModuleBuilder("env").ExportFunction("hello", hello).Instantiate(ctx, r)
+_, err := r.NewHostModuleBuilder("env").
+ NewFunctionBuilder().WithFunc(hello).Export("hello").
+ Instantiate(ctx, r)
```
Power users can now use `HostFunctionBuilder` to define functions that
won't use reflection. There are two choices of interfaces to use
depending on if that function needs access to the calling module or not:
`api.GoFunction` and `api.GoModuleFunction`. Here's an example defining
one.
```go
builder.WithGoFunction(api.GoFunc(func(ctx context.Context, params []uint64) []uint64 {
x, y := uint32(params[0]), uint32(params[1])
sum := x + y
return []uint64{sum}
}, []api.ValueType{api.ValueTypeI32, api.ValueTypeI32}, []api.ValueType{api.ValueTypeI32})
```
As you'll notice and as documented, this approach is more verbose and
not for everyone. If you aren't making a low-level library, you are
likely able to afford the 1us penalty for the convenience of reflection.
However, we are happy to enable this option for foundational libraries
and those with high performance requirements (like ourselves)!
Fixes#825
Signed-off-by: Adrian Cole <adrian@tetrate.io>
We at one point considered making `ModuleBuilder` create complete
WebAssembly binaries. However, we recently spun out
[wabin](https://github.com/tetratelabs/wabin), which allows this.
Meanwhile, the features in `ModuleBuilder` were confusing and misused.
For example, the only two cases memory was exported on GitHub were done
by accident. This is because host functions act on the guest's memory,
not their own.
Hence, this removes memory and globals from host side definitions, and
renames the type to HostModuleBuilder to clarify this is not ever going
to be used to construct normal Wasm binaries.
Most importantly, this simplifies the API and reduces a lot of code. It
is important to make changes like this, particularly deleting any
experimental things that didn't end up useful.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
Co-authored-by: Anuraag Agrawal <anuraaga@gmail.com>
This top-levels `api.FunctionDefinition` which was formerly
experimental, and also adds import metadata to it. Now, it holds all
metadata known at compile time.
Here are the public API visible changes:
* api.ExportedFunction - replaced with api.FunctionDefinition as it is
usable for all types of functions.
* api.Function - `.ParamTypes/ResultTypes()` are replaced with
`.Definition().
* api.FunctionDefinition - extracted from experimental and adds
`.Import()` to get the any imported module and function name.
* experimental.FunctionDefinition - replaced with
api.FunctionDefinition.
* experimental.FunctionListenerFactory - adds first arg of the
instantiated module name, as it can be different than compiled.
* wazero.CompiledModule - Adds `.ImportedFunctions()` and changes result
type of `.ExportedFunctions()` to api.FunctionDefinition.
Internally, logic to create function definition are consolidated between
host and wasm-defined functions, notably wasm.Module now includes
`.BuildFunctionDefinitions()` which reduces duplication in
wasm.ModuleInstance `.BuildFunctions()`,
This obviates #681 by deleting the `ExportedFunction` type which
overlaps with this information.
This fixes#637 as it includes more metadata including imports.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
Co-authored-by: Takeshi Yoneda <takeshi@tetrate.io>
This removes WithWorkDirFS and any other attempts to resolve the current directory (".") in host functions. This is a reaction to reality of compilers who track this inside wasm (not via host functions). One nice side effect is substantially simpler internal implementation of file-systems.
This also allows experimental.WithFS to block file access via passing nil.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This implements our own assertion library so that we can remove the
testify dependency. I've changed a lot of call sites so that we only
have to maintain a minimal amount of assertions.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This starts the process of removing all dependencies from wazero, by
isolating all assertions we use into a single file. This allows us to
port those assertions as we have time, and when twitchy is gone, the
project literally has no dependencies except go!
Signed-off-by: Adrian Cole <adrian@tetrate.io>
